Detection apparatus and method for refrigerant leakage of air source cooling only system

ABSTRACT

A device and a method for detecting a refrigerant leakage of an air source cooling-only system, wherein the detection method comprises S1: obtaining an operating parameter of an air-cooled cooling-only air source cooling-only system, wherein the operating parameter comprises at least a compressor speed or capacity; S2: comparing the operating parameter with a preset operating parameter interval; S3: updating a cumulative score when the operating parameter falls within the preset operating parameter interval; and S4: determining that a refrigerant leakage has occurred when the cumulative score exceeds a predefined cumulative score, and returning to step S1 when the cumulative score does not exceed the predefined cumulative score.

FOREIGN PRIORITY

This application claims priority to Chinese Patent Application No.201810330163.4, filed Apr. 13, 2018, and all the benefits accruingtherefrom under 35 U.S.C. § 119, the contents of which in its entiretyare herein incorporated by reference.

TECHNICAL FIELD

The present invention relates to the field of operation and maintenanceof cooling systems, and more particularly to a device for detecting arefrigerant leakage of an air source cooling-only system, which is usedfor monitoring whether a leakage has occurred in a cooling system. Thepresent invention further relates to a method for detecting arefrigerant leakage of an air source cooling-only system.

BACKGROUND ART

It is known that an air source cooling-only system generally uses arefrigerant to perform a refrigeration cycle operation. Duringoperation, the refrigerant may leakage from pipelines for a variety ofreasons. A cooling-only module may probably shut down due to a leakage,thereby resulting in economic losses, air pollution, and repair costs.

The existing air source cooling-only system is not capable ofautomatically detecting a refrigerant leakage. Although aspecial-purpose apparatus can be used to detect whether a leakage hasoccurred, such detection is time-consuming and expensive.

Accordingly, it is desirable to provide a device and a method fordetecting a refrigerant leakage of an air source cooling-only system,which is capable of automatically detecting an occurrence of arefrigerant leakage and reducing operating costs.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a device for detectinga refrigerant leakage of an air source cooling-only system, which canautomatically detect a refrigerant leakage and send an alarm signal.Another object of the present invention is to provide a method fordetecting a refrigerant leakage of an air source cooling-only system.

The objects of the present invention are achieved by the followingtechnical solutions:

A device for detecting a refrigerant leakage of an air sourcecooling-only system comprises: a data obtaining module, configured toobtain an operating parameter of the air source cooling-only system; adata comparison module, configured to compare the operating parameterwith a preset operating parameter interval; a cumulative score updatingmodule, configured to update a cumulative score when the operatingparameter falls within the preset operating parameter interval; and arefrigerant leakage determination module, configured to determine that arefrigerant leakage has occurred when the cumulative score exceeds apredefined cumulative score, and to continue to operate the dataobtaining module when the cumulative score does not exceed thepredefined cumulative score.

Optionally, the data comparison module comprises a compressor speed orcapacity comparison module; the compressor speed or capacity comparisonmodule is configured to compare the compressor speed or capacity with aminimum speed or capacity when the air source cooling-only system hasbeen continuously operated for a first predefined period of time and anabsolute value of a temperature difference between inlet and outletwater is less than a first predefined value; and the cumulative scoreupdating module is configured to increase the cumulative score by afirst score when the compressor speed or capacity is greater than orequal to the minimum speed or capacity.

Optionally, the data comparison module comprises a superheat comparisonmodule; the superheat comparison module is configured to compare asuperheat degree with a sum of a superheat degree setting value and athird predefined value when the air source cooling-only system has beencontinuously operated for the first predefined period of time, theabsolute value of the temperature difference between inlet and outletwater is not less than the first predefined value, a supercooling degreeis less than a second predefined value, and an expansion valve openingdegree is equal to a predefined opening degree; the cumulative scoreupdating module is configured to continue to operate the data obtainingmodule when the superheat degree is not greater than the sum of thesuperheat degree setting value and the third predefined value; and thecumulative score updating module is further configured to increase thecumulative score by a second score when the superheat degree is greaterthan the sum of the superheat degree setting value and the thirdpredefined value.

Optionally, the data comparison module comprises a first pressurecomparison module; the first pressure comparison module is configured tocompare a compressor discharge pressure with a first predefined pressurewhen the air source cooling-only system has been continuously operatedfor the first predefined period of time, the absolute value of thetemperature difference between inlet and outlet water is not less thanthe first predefined value, the supercooling degree is less than thesecond predefined value, and the expansion valve opening degree is notequal to the predefined opening degree; the cumulative score updatingmodule is configured to continue to operate the data obtaining modulewhen the compressor discharge pressure is not less than the firstpredefined pressure; and the cumulative score updating module is furtherconfigured to increase the cumulative score by a third score when thecompressor discharge pressure is less than the first predefinedpressure.

Optionally, the data comparison module comprises a supercooling degreecomparison module; the supercooling degree comparison module isconfigured to compare the supercooling degree with a predefinedsupercooling degree when the air source cooling-only system has beencontinuously operated for the first predefined period of time, theabsolute value of the temperature difference between inlet and outletwater is not less than the first predefined value, and the supercoolingdegree is not less than the second predefined value; the cumulativescore updating module is configured to continue to operate the dataobtaining module when the supercooling degree is not less than thepredefined supercooling degree; and the cumulative score updating moduleis further configured to increase the cumulative score by a fourth scorewhen the supercooling degree is less than the predefined supercoolingdegree.

Optionally, the data comparison module comprises a second pressurecomparison module and/or a reservoir level comparison module;

the second pressure comparison module and/or the reservoir levelcomparison module is configured to operate when a second predefinedperiod of time elapses after the air source cooling-only system is shutdown; and wherein the second pressure comparison module is configured tocompare the compressor discharge pressure of the air source cooling-onlysystem with a second predefined pressure, and/or the reservoir levelcomparison module is configured to compare a reservoir level with apredefined reservoir level; and the refrigerant leakage determinationmodule is configured to determine that the refrigerant leakage hasoccurred when the compressor discharge pressure of the air sourcecooling-only cycle system is less than the second predefined pressureand/or the reservoir level is below the predefined reservoir level.

Optionally, the preset operating parameter interval is a preset value, apreset table, or a preset diagram.

Optionally, the device further comprises a warning module configured tosend a leakage warning signal when it is determined that the refrigerantleakage has occurred.

Optionally, the first predefined value is 1 degree Celsius.

Optionally, the operating parameter comprises one or more of thefollowing: an operating state of the air source cooling-only system, ashutdown state of the air source cooling-only system, time elapsed sincethe air source cooling-only system is shut down, time elapsed since theair source cooling-only system operates, a water outlet temperature, awater inlet temperature, an expansion valve opening degree, asupercooling degree, a superheat degree, a compressor dischargepressure, and a reservoir level.

A method for detecting a refrigerant leakage of an air sourcecooling-only system comprises the following steps: S1: obtaining anoperating parameter of the air source cooling-only system; S2: comparingthe operating parameter with a preset operating parameter interval; S3:updating a cumulative score when the operating parameter falls withinthe preset operating parameter interval; S4: determining that arefrigerant leakage has occurred when the cumulative score exceeds apredefined cumulative score, and returning to step S1 when thecumulative score does not exceed the predefined cumulative score.

Optionally, in step S2, the compressor speed or capacity is comparedwith a minimum speed or capacity when the air source cooling-only systemhas been continuously operated for a first predefined period of time andan absolute value of a temperature difference between inlet and outletwater is less than a first predefined value; in step S3, the cumulativescore is increased by a first score when the compressor speed orcapacity is greater than or equal to the minimum speed or capacity, andthe method returns to step S1 when the compressor speed or capacity isless than the predefined speed or capacity.

Optionally, in step S2, a superheat degree is compared with a sum of asuperheat degree setting value and a third predefined value when the airsource cooling-only system has been continuously operated for the firstpredefined period of time, the absolute value of the temperaturedifference between inlet and outlet water is not less than the firstpredefined value, a supercooling degree is less than a second predefinedvalue, and an expansion valve opening degree is equal to a predefinedopening degree; and in step S3, the cumulative score is increased by asecond score when the superheat degree is greater than the sum of thesuperheat degree setting value and the third predefined value, and themethod returns to step S1 when the superheat degree is not greater thanthe sum of the superheat degree setting value and the third predefinedvalue.

Optionally, in step S2, a compressor discharge pressure is compared witha first predefined pressure when the air source cooling-only system hasbeen continuously operated for the first predefined period of time, theabsolute value of the temperature difference between inlet and outletwater is not less than the first predefined value, the supercoolingdegree is less than the second predefined value, and the expansion valveopening degree is not equal to the predefined opening degree; and instep S3, the cumulative score is increased by a third score when thecompressor discharge pressure is less than the first predefinedpressure, and the method returns to step S1 when the compressordischarge pressure is not less than the first predefined pressure.

Optionally, in step S2, the supercooling degree is compared with apredefined supercooling degree when the air source cooling-only systemhas been continuously operated for the first predefined period of time,the absolute value of the temperature difference between inlet andoutlet water is not less than the first predefined value, and thesupercooling degree is not less than the second predefined value; and instep S3, the cumulative score is increased by a fourth score when thesupercooling degree is less than the predefined supercooling degree, andthe method returns to step S1 when the supercooling degree is not lessthan the predefined supercooling degree.

Optionally, the method further comprises the following steps: S2.1: whena second predefined period of time elapses after the air sourcecooling-only system is shut down, comparing the compressor dischargepressure of the air source cooling-only system with a second predefinedpressure, and/or comparing a reservoir level with a predefined reservoirlevel; S3.1: determining that the refrigerant leakage has occurred whenthe compressor discharge pressure of the air source cooling-only systemis less than the second predefined pressure and/or the reservoir levelis below the predefined reservoir level.

Optionally, in step S2, the preset operating parameter interval is apreset value, a preset table, or a preset diagram.

Optionally, the method further comprises step S5: sending a warningsignal if it is determined that the refrigerant leakage has occurred.

Optionally, the first predefined value is 1 degree Celsius.

Optionally, step S1 comprises obtaining one or more of the followingoperating parameters: whether the air source cooling-only system isoperating, time elapsed since the air source cooling-only system is shutdown, time elapsed since the air source cooling-only system operates, awater outlet temperature, a water inlet temperature, the expansion valveopening degree, the supercooling degree, the superheat degree, thecompressor discharge pressure, and the reservoir level.

The device and the method for detecting a refrigerant leakage of an airsource cooling-only system according to the present invention are simpleand reliable, easy in implementation, convenient in application and soon, and can provide automatic detection of a refrigerant leakage,improving the operating efficiency and safety of modules.

DESCRIPTION OF THE DRAWINGS

The present invention will be described in further details below withreference to the accompanying drawings and preferred embodiments.However, those skilled in the art will understand that the drawings aredrawn only for explaining the preferred embodiments and thus should notbe taken as limiting the scope of the present invention. Moreover,unless expressly specified otherwise, the drawings are only intended toconceptually illustrate compositions or a construction of a describedobject and may comprise an exaggerated display, and the drawings are notnecessarily drawn to scale.

FIG. 1 is a schematic view of an embodiment of a device for detecting arefrigerant leakage of an air source cooling-only system according tothe present invention.

FIG. 2 is a flowchart of an embodiment of a method for detecting arefrigerant leakage of an air source cooling-only system according tothe present invention.

FIG. 3 is a detailed flowchart of the embodiment shown in FIG. 1.

DETAILED DESCRIPTION

The preferred embodiments of the present invention will be described indetail below with reference to the accompanying drawings. Those skilledin the art will understand that the description is only illustrative andexemplary, and should not be construed as limiting the scope of thepresent invention.

First of all, it is noted that positional terms such as top, bottom,upward, and downward mentioned herein are defined with respect todirections in each of the drawings, they are relative concepts and thuscan vary according to different locations and different practical statesthereof. Therefore, these or other positional terms should not beconstrued as limiting terms.

In addition, it is also noted that any single technical featuredescribed or implied in the embodiments herein or any single technicalfeature shown or implied in the drawings can still continue to becombined among these technical features (or equivalents thereof), so asto obtain other embodiments of the present invention that are notdirectly mentioned herein.

It should be noted that the same reference numbers in different figuresrefer to the same or substantially the same assemblies.

FIG. 1 is a schematic view of an embodiment of a device for detecting arefrigerant leakage of an air source cooling-only system according tothe present invention. Herein, the device for detecting a refrigerantleakage of an air source cooling-only system comprises a data obtainingmodule 100, configured to obtain an operating parameter of the airsource cooling-only system; a data comparison module 200, configured tocompare the operating parameter with a preset operating parameterinterval; a cumulative score updating module 300, configured to update acumulative score when the operating parameter falls within the presetoperating parameter interval; and a refrigerant leakage determinationmodule 400, configured to determine that a refrigerant leakage hasoccurred when the cumulative score exceeds a predefined cumulativescore, and to continue to operate the data obtaining module 100 when thecumulative score does not exceed the predefined cumulative score.

In one embodiment of the present invention, the data comparison module200 comprises a compressor speed or capacity comparison module 210. Thecompressor speed or capacity comparison module 210 is configured tocompare a compressor speed (compresser_spd) or capacity with a minimumspeed (minimum_spd) or capacity when the air source cooling-only systemhas been continuously operated for a first predefined period of time andan absolute value of a temperature difference between inlet and outletwater is less than a first predefined value; and the cumulative scoreupdating module 300 is configured to increase the cumulative score by afirst score when the compressor speed or capacity is greater than orequal to the minimum speed or capacity (as shown at module 310).

In another embodiment of the present invention, the data comparisonmodule 200 comprises a superheat comparison module 220; the superheatcomparison module 220 is configured to compare a superheat degree (SH)with a sum of a superheat degree setting value (SH_sp) and a thirdpredefined value (DT3) when the air source cooling-only system has beencontinuously operated for the first predefined period of time (N2), theabsolute value of the temperature difference between inlet and outletwater is not less than the first predefined value (DT1), a supercoolingdegree is less than a second predefined value (DT2), and an expansionvalve opening degree (EXV_open) is equal to a predefined opening degree;the cumulative score updating module 300 is configured to continue tooperate the data obtaining module 100 when the superheat degree is notgreater than the sum of the superheat degree setting value and the thirdpredefined value; and the cumulative score updating module 300 isfurther configured to increase the cumulative score by a second scorewhen the superheat degree is greater than the sum of the superheatdegree setting value and the third predefined value (as shown at module320).

In another embodiment of the present invention, the data comparisonmodule 200 comprises a first pressure comparison module 230; the firstpressure comparison module 230 is configured to compare a compressordischarge pressure (HP) with a first predefined pressure (HP_predefined)when the air source cooling-only system has been continuously operatedfor the first predefined period of time, the absolute value of thetemperature difference between inlet and outlet water is not less thanthe first predefined value, the supercooling degree is less than thesecond predefined value, and the expansion valve opening degree is notequal to the predefined opening degree; the cumulative score updatingmodule 300 is configured to continue to operate the data obtainingmodule 100 when the compressor discharge pressure (HP) is not less thanthe first predefined pressure; and the cumulative score updating module300 is further configured to increase the cumulative score by a thirdscore when the compressor discharge pressure (HP) is less than the firstpredefined pressure (as shown at module 330).

In another embodiment of the present invention, the data comparisonmodule 200 comprises a supercooling degree comparison module 240; thesupercooling degree comparison module 240 is configured to compare thesupercooling degree (SC) with a predefined supercooling degree(SC_predefined) when the air source cooling-only system has beencontinuously operated for the first predefined period of time, theabsolute value of the temperature difference between inlet and outletwater is not less than the first predefined value, and the supercoolingdegree is not less than the second predefined value; the cumulativescore updating module 300 is configured to continue to operate the dataobtaining module 100 when the supercooling degree is not less than thepredefined supercooling degree; and the cumulative score updating module300 is further configured to increase the cumulative score by a fourthscore when the supercooling degree is less than the predefinedsupercooling degree (as shown at module 340).

In another embodiment of the present invention, the data comparisonmodule 200 comprises a second pressure comparison module and/or areservoir level comparison module 250; the second pressure comparisonmodule and/or the reservoir level comparison module 250 is configured tooperate when a second predefined period of time (N1) elapses after theair source cooling-only system is shut down; and wherein the secondpressure comparison module is configured to compare the compressordischarge pressure of the air source cooling-only system with a secondpredefined pressure, and/or the reservoir level comparison module isconfigured to compare a reservoir level with a predefined reservoirlevel; and the refrigerant leakage determination module 400 isconfigured to determine that the refrigerant leakage has occurred whenthe compressor discharge pressure of the air source cooling-only systemis less than the second predefined pressure and/or the reservoir levelis below the predefined reservoir level.

In the embodiments of the present invention, the preset operatingparameter interval may be a preset value, a preset table, or a presetdiagram. The preset value, preset table, or preset diagram can bepre-stored in a memory.

The device for detecting a refrigerant leakage according to the presentinvention can further comprise a warning module 500 configured to send aleakage warning signal when the refrigerant leakage determination module400 determines that the refrigerant leakage has occurred. The warningsignal can be an image signal, a sound signal, or a combination thereof.

In one embodiment of the present invention, the first predefined valueis 1 degree Celsius.

In one embodiment of the present invention, the predefined openingdegree is 100%.

In one embodiment of the present invention, the operating parametercomprises one or more of the following: an operating state of the airsource cooling-only system, a shutdown state of the air sourcecooling-only system, time elapsed since the air source cooling-onlysystem is shut down, time elapsed since the air source cooling-onlysystem operates, a water outlet temperature, a water inlet temperature,an expansion valve opening degree, a supercooling degree, a superheatdegree, a compressor discharge pressure, and a reservoir level.

FIG. 2 is a flowchart of an embodiment of a method for detecting arefrigerant leakage of an air source cooling-only system according tothe present invention. Herein, the method for detecting a refrigerantleakage of an air source cooling-only system comprises the followingsteps:

S1: obtaining an operating parameter of the air source cooling-onlysystem;

S2: comparing the operating parameter with a preset operating parameterinterval;

S3: updating a cumulative score when the operating parameter fallswithin the preset operating parameter interval;

S4: determining that a refrigerant leakage has occurred when thecumulative score exceeds a predefined cumulative score, and returning tostep S1 when the cumulative score does not exceed the predefinedcumulative score.

In one embodiment of the present invention, in step S2, the compressorspeed or capacity is compared with a minimum speed or capacity when theair source cooling-only system has been continuously operated for afirst predefined period of time and an absolute value of a temperaturedifference between inlet and outlet water is less than a firstpredefined value; and in step S3, the cumulative score is increased by afirst score when the compressor speed or capacity is greater than orequal to the minimum speed or capacity, and the method returns to stepS1 when the compressor speed or capacity is less than the predefinedspeed or capacity.

In another embodiment of the present invention, in step S2, a superheatdegree is compared with a sum of a superheat degree setting value and athird predefined value when the air source cooling-only system has beencontinuously operated for the first predefined period of time, theabsolute value of the temperature difference between inlet and outletwater is not less than the first predefined value, a supercooling degreeis less than a second predefined value, and an expansion valve openingdegree is equal to a predefined opening degree; and in step S3, thecumulative score is increased by a second score when the superheatdegree is greater than the sum of the superheat degree setting value andthe third predefined value, and the method returns to step S1 when thesuperheat degree is not greater than the sum of the superheat degreesetting value and the third predefined value.

In another embodiment of the present invention, in step S2, a compressordischarge pressure is compared with a first predefined pressure when theair source cooling-only system has been continuously operated for thefirst predefined period of time, the absolute value of the temperaturedifference between inlet and outlet water is not less than the firstpredefined value, the supercooling degree is less than the secondpredefined value, and the expansion valve opening degree is not equal tothe predefined opening degree; and in step S3, the cumulative score isincreased by a third score when the compressor discharge pressure isless than the first predefined pressure, and the method returns to stepS1 when the compressor discharge pressure is not less than the firstpredefined pressure.

In another embodiment of the present invention, in step S2, thesupercooling degree is compared with a predefined supercooling degreewhen the air source cooling-only cycle system has been continuouslyoperated for the first predefined period of time, the absolute value ofthe temperature difference between inlet and outlet water is not lessthan the first predefined value, and the supercooling degree is not lessthan the second predefined value; and in step S3, the cumulative scoreis increased by a fourth score when the supercooling degree is less thanthe predefined supercooling degree, and the method returns to step S1when the supercooling degree is not less than the predefinedsupercooling degree.

In one embodiment of the present invention, the method further comprisesthe following steps:

S2.1: when a second predefined period of time elapses after the airsource cooling-only system is shut down, comparing the compressordischarge pressure of the air source cooling-only system with a secondpredefined pressure, and/or comparing a reservoir level with apredefined reservoir level; and

S3.1: determining that the refrigerant leakage has occurred when thecompressor discharge pressure of the air source cooling-only system isless than the second predefined pressure and/or the reservoir level isbelow the predefined reservoir level.

In one embodiments of the present invention, the preset operatingparameter interval described in step S2 may be a preset value, a presettable, or a preset diagram. The preset value, preset table, or presetdiagram can be stored in an accessible memory.

In one embodiments of the present invention, the method furthercomprises step S5 in which a warning signal is sent if it is determinedthat the refrigerant leakage has occurred. The warning signal can be animage signal, a sound signal, or a combination thereof.

In one embodiment of the present invention, the first predefined valueis 1 degree Celsius.

In one embodiment of the present invention, the predefined openingdegree is 100%.

In one embodiment of the present invention, step S1 comprises obtainingone or more of the following operating parameters: whether the airsource cooling-only system is operating, time elapsed since the airsource cooling-only system is shut down, time elapsed since the airsource cooling-only system operates, a water outlet temperature, a waterinlet temperature, an expansion valve opening degree, a supercoolingdegree, a superheat degree, a compressor discharge pressure, and areservoir level.

FIG. 3 is a detailed flowchart of the embodiment shown in FIG. 1.Herein, when a cooling system is in a cooling mode, whether the coolingsystem is operating is continuously monitored. If it is found that thesystem has been shut down for a longer duration than a second predefinedperiod of time, steps S2.1 and S3.1 described above are performed; andwhen it is determined that a refrigerant leakage has occurred, a warningsignal is sent.

If it is found that the system has been operated for a longer durationthan a first predefined period of time, then whether an absolute valueof a temperature difference between inlet and outlet water is less thana first predefined value is detected. If the absolute value of thetemperature difference between inlet and outlet water is less than thefirst predefined value, then a compressor speed or capacity check isperformed.

If the absolute value of the temperature difference between inlet andoutlet water is not less than the first predefined value, then anoperating parameter of an air-cooled heat pump system is obtained,including reading an expansion valve opening degree, a supercoolingdegree, and a superheat degree from the air-cooled heat pump system; andwhether the supercooling degree is less than a second predefined valueis determined. If the supercooling degree is not less than the secondpredefined value, then a supercooling degree check is performed.

If the supercooling degree is less than the second predefined value,then whether the expansion valve opening degree is equal to a predefinedopening degree is determined continuously; if the expansion valveopening degree is equal to the predefined opening degree, then asuperheat degree check is performed; and if the expansion valve openingdegree is not equal to the predefined opening degree, then a compressordischarge pressure check is performed.

In each of the checking steps described above, if a checked operatingparameter falls within a predefined range, then a cumulative score isrespectively increased by a different value. When the cumulative scorereaches a predefined cumulative score, it is determined that arefrigerant leakage has occurred and a warning signal is sent. Herein,in the compressor speed or capacity check, if a compressor speed orcapacity is greater than or equal to a minimum speed or capacity, thecumulative score is increased by a first score; in the superheat degreecheck, if a superheat degree is greater than a sum of a superheat degreesetting value and a third predefined value, the cumulative score isincreased by a second score; in the compressor discharge pressure check,if a compressor discharge pressure is less than a first predefinedpressure, the cumulative score is increased by a third score; and in thesupercooling degree check, if a supercooling degree is less than apredefined supercooling degree, the cumulative score is increased by afourth score. Herein, each of the checking steps described above can beused alone or in combination; and when a combination is performed, twoor more than two or all of the checking steps can be used.

In one embodiment of the invention, an initial value of the cumulativescore is 0; the first score is 5; the second score is 3; the third scoreis 2; and the fourth score is 1. When the cumulative score reaches 15(i.e., the predefined cumulative score), it is determined that arefrigerant leakage has occurred and a leakage warning signal is sent.

The device and the method for detecting a refrigerant leakage accordingto the present invention are applicable to an air source cooling-onlycycle cooling system which is preferably air-cooled. The device and themethod for detecting a refrigerant leakage according to the presentinvention can automatically detect whether a refrigerant leakage hasoccurred in a cooling system without using other apparatuses for manualdetection, which effectively improves the operating efficiency of thecooling system and has good economic benefits.

The specification discloses the present invention with reference to thedrawings, and also allows those skilled in the art to implement thepresent invention, including making and using any device or module,selecting a suitable material, and using any combined method. The scopeof the present invention is defined by the claimed technical solutions,and includes other examples that are envisaged by those skilled in theart. As long as such other examples contain structural elements that arenot different from the literal language of the claimed technicalsolutions, or such other examples contain equivalent structural elementsthat are not substantially different from the literal language of theclaimed technical solutions, such other examples should be consideredwithin the scope defined by the technical solutions claimed by thepresent invention.

What is claimed is:
 1. A device for detecting a refrigerant leakage of an air source cooling-only cycle system, comprising: a data obtaining module, configured to obtain an operating parameter of the air source cooling-only cycle system, wherein the operating parameter comprises at least a compressor speed or capacity; a data comparison module, configured to compare the operating parameter with a preset operating parameter interval; a cumulative score updating module, configured to update a cumulative score when the operating parameter falls within the preset operating parameter interval; and a refrigerant leakage determination module, configured to determine that a refrigerant leakage has occurred when the cumulative score exceeds a predefined cumulative score, and to continue to operate the data obtaining module when the cumulative score does not exceed the predefined cumulative score.
 2. The device for detecting a refrigerant leakage according to claim 1, wherein the data comparison module comprises a compressor speed or capacity comparison module; the compressor speed or capacity comparison module is configured to compare the compressor speed or capacity with a predefined speed or capacity when the air source cooling-only cycle system has been continuously operated for a first predefined period of time and an absolute value of a temperature difference between inlet and outlet water is less than a first predefined value; and the cumulative score updating module is configured to increase the cumulative score by a first score when the compressor speed or capacity is greater than or equal to the predefined speed or capacity.
 3. The device for detecting a refrigerant leakage according to claim 2, wherein the data comparison module comprises a superheat comparison module; the superheat comparison module is configured to compare a superheat degree with a sum of a superheat degree setting value and a third predefined value when the air source cooling-only cycle system has been continuously operated for the first predefined period of time, the absolute value of the temperature difference between inlet and outlet water is not less than the first predefined value, a supercooling degree is less than a second predefined value, and an expansion valve opening degree reaches a predefined opening degree; the cumulative score updating module is configured to continue to operate the data obtaining module when the superheat degree is not greater than the sum of the superheat degree setting value and the third predefined value; and the cumulative score updating module is further configured to increase the cumulative score by a second score when the superheat degree is greater than the sum of the superheat degree setting value and the third predefined value.
 4. The device for detecting a refrigerant leakage according to claim 3, wherein the data comparison module comprises a first pressure comparison module; the first pressure comparison module is configured to compare a compressor discharge pressure with a first predefined pressure when the air source cooling-only cycle system has been continuously operated for the first predefined period of time, the absolute value of the temperature difference between inlet and outlet water is not less than the first predefined value, the supercooling degree is less than the second predefined value, and the expansion valve opening degree is not equal to the predefined opening degree; the cumulative score updating module is configured to continue to operate the data obtaining module when the compressor discharge pressure is not less than the first predefined pressure; and the cumulative score updating module is further configured to increase the cumulative score by a third score when the compressor discharge pressure is less than the first predefined pressure.
 5. The device for detecting a refrigerant leakage according to claim 4, wherein the data comparison module comprises a supercooling degree comparison module; the supercooling degree comparison module is configured to compare the supercooling degree with a predefined supercooling degree when the air source cooling-only cycle system has been continuously operated for the first predefined period of time, the absolute value of the temperature difference between inlet and outlet water is not less than the first predefined value, and the supercooling degree is not less than the second predefined value; the cumulative score updating module is configured to continue to operate the data obtaining module when the supercooling degree is not less than the predefined supercooling degree; and the cumulative score updating module is further configured to increase the cumulative score by a fourth score when the supercooling degree is less than the predefined supercooling degree.
 6. The device for detecting a refrigerant leakage according to claim 1, wherein the device further comprises: the data comparison module comprising a second pressure comparison module and/or a reservoir level comparison module; the second pressure comparison module and/or the reservoir level comparison module is configured to operate when a second predefined period of time elapses after the air source cooling-only cycle system is shut down; and wherein the second pressure comparison module is configured to compare the compressor discharge pressure with a second predefined pressure, and/or the reservoir level comparison module is configured to compare a reservoir level with a predefined reservoir level; and the refrigerant leakage determination module is configured to determine that the refrigerant leakage has occurred when the compressor discharge pressure of the air source cooling-only cycle system is less than the second predefined pressure and/or the reservoir level is below the predefined reservoir level.
 7. The device for detecting a refrigerant leakage according to claim 1, wherein the preset operating parameter interval is a preset value, a preset table, or a preset diagram.
 8. The device for detecting a refrigerant leakage according to claim 1, wherein the device further comprises: a warning module, configured to send a leakage warning signal when it is determined that the refrigerant leakage has occurred.
 9. The device for detecting a refrigerant leakage according to claim 2, wherein the first predefined value is 1 degree Celsius.
 10. The device for detecting a refrigerant leakage according to claim 1, wherein the operating parameter comprises one or more of the following: an operating state of the air source cooling-only cycle system, a shutdown state of the air source cooling-only cycle system, time elapsed since the air source cooling-only cycle system is shut down, time elapsed since the air source cooling-only cycle system operates, a water outlet temperature, a water inlet temperature, an expansion valve opening degree, a supercooling degree, a superheat degree, a compressor discharge pressure, and a reservoir level.
 11. A method for detecting a refrigerant leakage of an air source cooling-only cycle system, comprising the following steps: S1: obtaining an operating parameter of the air source cooling-only cycle system, wherein the operating parameter comprises at least a compressor speed or capacity; S2: comparing the operating parameter with a preset operating parameter interval; S3: updating a cumulative score when the operating parameter falls within the preset operating parameter interval; S4: determining that a refrigerant leakage has occurred when the cumulative score exceeds a predefined cumulative score, and returning to step S1 when the cumulative score does not exceed the predefined cumulative score.
 12. The method for detecting a refrigerant leakage according to claim 11, wherein in step S2, the compressor speed or capacity is compared with a predefined speed or capacity when the air source cooling-only cycle system has been continuously operated for a first predefined period of time and an absolute value of a temperature difference between inlet and outlet water is less than a first predefined value; and in step S3, the cumulative score is increased by a first score when the compressor speed or capacity is greater than or equal to the predefined speed or capacity, and the method returns to step S1 when the compressor speed or capacity is less than the predefined speed or capacity.
 13. The method for detecting a refrigerant leakage according to claim 12, wherein in step S2, a superheat degree is compared with a sum of a superheat degree setting value and a third predefined value when the air source cooling-only cycle system has been continuously operated for the first predefined period of time, the absolute value of the temperature difference between inlet and outlet water is not less than the first predefined value, a supercooling degree is less than a second predefined value, and an expansion valve opening degree is equal to a predefined opening degree; in step S3, the cumulative score is increased by a second score when the superheat degree is greater than the sum of the superheat degree setting value and the third predefined value, and the method returns to step S1 when the superheat degree is not greater than the sum of the superheat degree setting value and the third predefined value.
 14. The method for detecting a refrigerant leakage according to claim 13, wherein in step S2, a compressor discharge pressure is compared with a first predefined pressure when the air source cooling-only cycle system has been continuously operated for the first predefined period of time, the absolute value of the temperature difference between inlet and outlet water is not less than the first predefined value, the supercooling degree is less than the second predefined value, and the expansion valve opening degree is not equal to the predefined opening degree; in step S3, the cumulative score is increased by a third score when the compressor discharge pressure is less than the first predefined pressure, and the method returns to step S1 when the compressor discharge pressure is not less than the first predefined pressure.
 15. The method for detecting a refrigerant leakage according to claim 14, wherein in step S2, the supercooling degree is compared with a predefined supercooling degree when the air source cooling-only cycle system has been continuously operated for the first predefined period of time, the absolute value of the temperature difference between inlet and outlet water is not less than the first predefined value, and the supercooling degree is not less than the second predefined value; in step S3, the cumulative score is increased by a fourth score when the supercooling degree is less than the predefined supercooling degree, and the method returns to step S1 when the supercooling degree is not less than the predefined supercooling degree.
 16. The method for detecting a refrigerant leakage according to claim 11, wherein the method further comprises the following steps: S2.1: when a second predefined period of time elapses after the air source cooling-only cycle system is shut down, comparing the compressor discharge pressure of the air source cooling-only cycle system with a second predefined pressure, and/or comparing a reservoir level with a predefined reservoir level; S3.1: determining that the refrigerant leakage has occurred when the compressor discharge pressure of the air source cooling-only cycle system is less than the second predefined pressure and/or the reservoir level is below the predefined reservoir level.
 17. The method for detecting a refrigerant leakage according to claim 11, wherein in step S2, the preset operating parameter interval is a preset value, a preset table, or a preset diagram.
 18. The method for detecting a refrigerant leakage according to claim 11, wherein the method further comprises: step S5: sending a warning signal if it is determined that the refrigerant leakage has occurred.
 19. The method for detecting a refrigerant leakage according to claim 12, wherein the first predefined value is 1 degree Celsius.
 20. The method for detecting a refrigerant leakage according to claim 11, wherein step S1 comprises obtaining one or more of the following operating parameters: whether the air source cooling-only cycle system is operating, time elapsed since the air source cooling-only cycle system is shut down, time elapsed since the air source cooling-only cycle system operates, a water outlet temperature, a water inlet temperature, an expansion valve opening degree, a supercooling degree, a superheat degree, a compressor discharge pressure, and a reservoir level. 